JPH03214184A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device which controls a paper guide surface from becoming a high temperature by making an edge surface of a metal plate to be the paper guide surface. CONSTITUTION:The paper guide mechanism 73 is constituted with a multiple number of metal plates having the edge surfaces installed facing a flash fixing device, and the edge surfaces are the paper guiding surfaces 51a. Thus, the temperature rise of the paper guide surfaces 51a of the paper guide mechanism 73 in the flash fixing means can be controlled, toner adhering is not generated to the paper guide surface 51a even when both side printing is carried out, paper soiling does not occur, quality deterioration of printing can be prevented, and the initial good printing quality can be maintained over a long period of time.

Description

[Detailed Description of the Invention] [Summary] Regarding the structure of the paper guide mechanism of the flash fixing means of an image forming apparatus, the purpose is to suppress the paper guide surface from becoming high temperature, and to prevent the paper to which the toner has been transferred. A flash fixing means is provided, in which a flash fixing device that emits flash light, a paper transport device consisting of a paper transport mechanism, and a paper guide mechanism that guides the transported paper are arranged facing each other. In the image forming apparatus, the paper guide mechanism is configured such that a plurality of metal plates are disposed with their end faces facing the flash fixing device, and the end faces serve as paper guide surfaces.

[Industrial application field]

The present invention relates to the structure of a paper guide mechanism of a flash fixing means of an image forming apparatus.

Since the paper guide mechanism of the flash fixing means is irradiated with flash light, the temperature of the paper guide surface tends to rise.

When the temperature of the paper guide surface rises above the specified temperature,
Since various inconveniences occur, the paper guide mechanism needs to have a structure in which the temperature does not easily rise.

[Conventional technology]

FIG. 6 shows a conventional example. 1 is a photosensitive drum, and 2 is a flash fixing means.

The flash fixing means 2 includes a flash fixing device 3 and a paper conveyor 4.

The paper conveyance device 4 includes a paper conveyance mechanism 5 consisting of a suction rotating roller, and a plurality of paper guides 6 on which the conveyed paper is guided so as to slide thereon.

The paper guide 6 is an elongated sheet metal member, and a plurality of paper guides 6 are arranged parallel to each other in the paper conveyance direction indicated by an arrow 7.

The paper 8 on which the tonneau on the latent image formed on the surface of the photosensitive drum 1 has been transferred is transferred to a paper guide 6 by a paper transport mechanism 5.
The image is guided through the flash fixing means 2, and is irradiated with flash light from the flash fixing section 3 to be fixed.

During double-sided printing, the paper 8a sent out from the flash fixing means 2 is conveyed as shown by the arrow 9, its back side is attached to the photosensitive drum 1, the paper is transferred to the back surface, and then it is transferred inside the flash fixing means 2. It passes through and becomes established.

[Problem to be solved by the invention]

The paper guide 6 has a structure in which an elongated sheet metal member is disposed with its upper surface facing the flash fixing section 3, and its temperature rises when it is irradiated with flash light.

When the temperature of the paper guide 6 increases, the following problems occur.

(2) During the process of fixing the back side of the double-sided printing operation, the toner on the front side adheres to the paper guide 6. This adhered toner adheres to the paper that is then conveyed, staining the paper, and impairing print quality.

- There is a risk of burns to the operator when removing the jammed paper from the fixing means 2.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can prevent a paper guide surface from becoming high temperature.

[Means to solve the problem]

In the invention of claim 1, a flash fixing device that irradiates a flash light onto a sheet of paper onto which toner has been transferred, and a paper transport device that includes a mechanism that transports the paper and a paper guide mechanism that guides the transported paper are opposite to each other. In an image forming apparatus having a flash fixing device, the paper guide mechanism is arranged such that a plurality of metal plates are arranged with their end faces facing the flash fixing device, and the end faces are arranged to face the flash fixing device. It is configured to serve as a guide surface.

According to a second aspect of the present invention, the paper guide mechanism further includes a heat pipe having a radiation fin at an end to release heat from the metal plate.

[Effect]

By using the end face of the metal plate as the paper guide surface, the paper guide mechanism has a narrow area that is irradiated with flash light and a large area that radiates heat, thereby suppressing the rise in temperature of the paper guide surface.

A heat pipe having radiation fins at its end effectively suppresses the rise in temperature of the paper guide surface.

〔Example〕

FIG. 2 shows a schematic diagram of the overall configuration of an image forming apparatus 20 according to an embodiment of the present invention.

In the figure, 21 is a photosensitive drum as an image carrier.

Reference numeral 22 denotes a flash fixing means, which includes a flash fixing device 23 that emits flash light, and a paper conveyor 24 facing the flash fixing device 23.

Around the photosensitive drum 21, a pre-charger 25. a light device 26
．． Developing device 27. A transfer device 28 and a cleaner 29 are provided.

Printing by this image forming apparatus 20 is performed as follows.

The surface of the photosensitive drum 21, which rotates in the clockwise direction indicated by an arrow 30, is first uniformly charged by the front charger 25, and then a latent image corresponding to the recorded image is formed thereon by the exposure device 26. This latent image is developed by a developing device 27 to become a toner image, and the toner image is transferred by a transfer device 28 onto a sheet 32 fed from a sheet feeding section 31. Then paper 32
is transported in the direction of arrow 33 by the transport section 24, and the toner image is fixed by the flash fixing device 23. Then paper 3
2 is discharged to the stacker section by the discharge roller 34.

In the above explanation, an example was described in which printing is performed only on the front side of the paper, but when printing on both sides of the paper, the fuser 2
The paper on which the fixing in step 3 has been completed is transported to the paper reversing mechanism 35 for processing by switching the transport path by a transport path switching means (not shown).

The paper 32 is conveyed along a path 36 as shown by an arrow 37, turned over, and fed between the photosensitive drum 21 and the transfer device 28 with the back side facing up, where it is transferred onto the back side. , is fixed by the fixing device 23.

Next, the structure of the paper conveyor 24 will be explained with reference to FIG. 1 and the like.

FIG. 1 shows the paper transporter 24. As shown in FIG.

Reference numeral 40 denotes suction rollers as a paper transport mechanism, and as shown in FIGS. 1 and 3, there are three rows in the paper transport direction 33, and a plurality of suction rollers are provided in each row.

Each suction roller 40 has a plurality of suction holes formed on its circumferential surface, and the suction hole that reaches the top side performs suction while rotating in the direction of arrow 41, imparting a conveying force to the paper 32, and the paper 32 is It is transported in the direction of arrow 33.

In FIG. 1, for convenience of illustration, the suction roller 40 is
This is indicated by the two-dot chain line.

50 is a paper guide mechanism main body, and as shown in FIGS. 3 and 4, a paper guide plate 51 in the shape of two 1 characters arranged horizontally is oriented vertically, and a plurality of paper guide plates 51 are arranged at intervals. It has a structure in which the sheets are arranged in an am-shape parallel to the paper conveyance direction 33.

Each paper guide plate 51 is arranged between the suction rollers 4o,
The end surface 51a, which is the top of the character 1, becomes the paper guide surface.

The width W of the paper guide surface 51a corresponds to the thickness t of the paper guide plate 51, and is about 3 to 5 am T-, which is narrower than that of the conventional paper guide plate 51 by about 1/10.

Further, a Teflon (registered trademark) coating 52 is applied to the paper guide surface 51a of the paper guide plate 51. This is to make it difficult for toner to adhere.

Further, the paper guide plate 51 is made of copper and has high thermal conductivity.

Further, each paper guide plate 51 has a pair of leg portions 51b, 51
c are respectively brazed and integrated with copper vias 53 and 54, and together with brackets 55 and 56 fixed to both ends of the copper vias 53 and 54, the paper guide mechanism main body 50 is constructed.

The copper vibrators 53 and 54, the paper guide plate 51, and the brackets 55 and 56 are brazed together.

57 is the brazing section.

The inner diameter of the copper vibrator 53.54 is slightly larger than 13mg+.

The paper guide mechanism main body 50 has brackets 55.5 on both sides.
6 is fixed and attached to a copper plate (not shown), and each paper guide plate 51 is vertical, arranged between adjacent suction rollers 40, and aligned in the paper conveyance direction 33.

The paper guide surface 51a supports the paper 32 so that the paper 32 being conveyed does not get drawn between the suction rollers 40 adjacent in the conveyance direction, and also guides the paper 32 so that it slides.

In FIG. 1, 60 is a heat pipe assembly, and as shown in FIG. There are 5 questions and 7 to 8 cards are fixed.

The heat dissipation fin 62 is fixed to the heat pipe 1 by fitting the hole 62a, which is burred, into the heat pipe 1.

Among the radiation fins 62, the one 62-1 on the inner side has two bent portions 52-1a formed therein for attachment.

60A is a heat pipe assembly, which, like the heat pipe assembly 60 described above, has a structure in which a plurality of heat radiation fins 62A are fixed to one end side of the heat pipe 1A.

As shown in FIG. 1, the heat pipe assembly 60.6OA includes a heat pipe 1.61A and a copper vibrator 53.6OA, respectively.
54, the radiation fin 62-L 62
A-1 is screwed and attached to the copper plate 70 with screws 68 and 69, and the radiation fins 62 and 62A protrude outward from the side plate 70.

Reference numeral 71 denotes a cooling fan, which is provided below the radiation fins 62 and 62A, and blows air onto the radiation fins 62 and 62A as indicated by an arrow 72 to forcefully cool the radiation fins 67.

The above paper guide mechanism main body 50. Heat pipe assembly 6
0.60A and the cooling fan 71 constitute the paper guide mechanism 73.

Next, the operation of the paper guide mechanism 73 described above will be explained.

The flash light from the flash fixing device 23 illuminates the paper guide surface 51a of the paper guide mechanism 73, and the paper guide plate 51 is heated.

Here, the paper guide surface 51a that is irradiated with flash light is extremely narrow and has a narrow area.

Further, the leg portions 51b and 51c of the paper guide plate 51 also function as a heat radiating portion. The area of the heat dissipation part is relatively large.

In this way, each paper guide plate 51 has a narrow area irradiated with flash light and a relatively wide heat dissipation section, so that
The paper guide 51a is less likely to become hot than in the past.

Furthermore, the heat of the paper guide plate 51 is transmitted through a heat pipe 66.6.
Radiation fin 6 that conducts 6A well and is forced air cooled
Heat is radiated from 7.67A.

Therefore, the temperature of the paper guide surface 51a is further suppressed from increasing, and is kept at a temperature sufficiently lower than the temperature at which the toner is melted.

As a result, when printing on the back side of the paper after printing on the front side, even if the toner already fixed on the front side rubs against the paper guide surface 51a while the paper is being conveyed through the fixing means 22, the toner will not be applied to the paper. It does not transfer to and adhere to the guide surface 51a.

The Teflon coating 52 also functions to prevent toner from adhering.

This prevents the inconvenience of paper being smeared with toner and print quality deteriorating.

Further, even if the operator touches the paper guide surface 51a during the operation of removing the jammed paper from the flash fixing means 22, the operator will not be burned.

Note that the heat pipe assembly 60.6OA is separate from the paper guide mechanism main body 50 and is removable. Therefore, when the heat pipe assembly 60 or 60A breaks down, it is sufficient to leave the paper guide mechanism main body 60 as it is and remove and replace the faulty heat pipe assembly, resulting in good maintainability.

〔Effect of the invention〕

As described above, according to the first aspect of the invention, it is possible to suppress the temperature rise of the paper guide surface of the paper guide mechanism in the flash fixing means.

As a result, even when double-sided printing is performed, toner does not adhere to the paper guide surface, so the paper does not become stained, preventing deterioration in print quality, and maintaining good initial print quality over a long period of time. .

Furthermore, it is possible to eliminate burns caused by workers during maintenance work to remove jammed paper from the flash fixing means.

According to the invention of claim 2, it is possible to further suppress the rise in temperature of the paper guide surface, to more reliably prevent toner from adhering to the paper guide surface, and to more reliably prevent deterioration of print quality. I can do it.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a paper transporter which is a main part of the present invention, Fig. 2 is a diagram showing the overall schematic configuration of an image forming apparatus according to an embodiment of the invention, and Fig. 3 is a side view of the paper transporter. 4 is a diagram showing the main body of the paper guide mechanism, FIG. 5 is a diagram showing a heat pipe assembly, and FIG. 6 is a diagram showing a conventional example. In the figure, 20 is an image forming device, 21 is a photosensitive drum, 22 is a flash fixing unit, 23 is a flash fixer, 24 is a paper conveyor, 40 is a @ forming roller (paper conveyance mechanism), 50 is a paper guide mechanism main body, 51 is a copper paper guide plate, 51a is a paper guide surface, 51G is a leg, 52 is a Teflon coating, 53.54 is a copper vibe, 60.60A is a heat pipe assembly, 61.61A is a heat pipe, 62 .62A is a radiation fin, 68.69 is a screw, 70 is a side plate, 71 is a cooling fan, 72 is an air flow, and 73 is a paper guide mechanism.

Claims (2)

[Claims] (1) Paper transport consisting of a flash fixing device (23) that irradiates flashlight onto the paper onto which toner has been transferred, a mechanism (40) that transports the paper, and a paper guide mechanism (73) that guides the transported paper. In the image forming apparatus, the paper guide mechanism (73) is connected to a plurality of metal plates (51).
is disposed with its end face facing the flash fixing device, and the end face serves as a paper guide surface (51a). (2) The paper guide mechanism further includes a heat pipe (61, 61A) having a radiation fin (67) at an end to release heat from the metal plate. image forming device.